Rapid diagnosis of pneumonia in children

Antigen detection techniques are available for the identification of bacterial polysaccharides, viruses, and chlamydia. Viruses and chlamydia are detected by direct immunofluorescence (DFA) or enzyme immunoassay (EIA). Bacterial polysaccharides are detected by latex agglutination or staphylococcal coagglutination of serum or concentrated urine. Most studies have not compared these techniques to the gold standard of lung puncture, so the role of dual infections with bacteria and viruses cannot be adequately determined. The sensitivity of any of these techniques is dependent on the quality of the antisera used. Monoclonal sera are now available for the detection of most viruses and seem to be as sensitive as polyclonal sera. DFA or EIA may offer equal sensitivity but their advantages and disadvantages must be considered by the local diagnostic laboratories. Most DFA and EIA systems have a sensitivity of 90% when compared with viral cultural for the identification of the organism. Agglutination reagents are available commercially for the detection of pneumococcal and Hemophilus influenzae type b polysaccharides. The sensitivity and specificity of each brand should be determined on serum or urine from patients known to have positive blood cultures and those free of disease. The brand chosen should be the one that has reasonable sensitivity and specificity. Rapid diagnostic techniques are helpful if they are used within a clinical context and they are positive. Negative tests do not rule out infection.     

Prolongation of allograft and xenograft survival in mice by anti-CD2 monoclonal antibodies.

Anti-CD2 monoclonal antibodies (mAb) were used to influence graft survival in two transplantation models. Xenogeneic rat islets were transplanted intraportally into mice. Anti-CD2 mAb prolonged xenograft survival and was synergistic with UVB irradiation in prolonging survival. Anti-CD2 mAb was also more potent than an anti-CD4 mAb in this model. Allogeneic cardiac grafts were transplanted across an entire H-2 difference and anti-CD2 mAb prolonged allograft survival in a dose-dependent fashion. Kinetic experiments revealed that anti-CD2 mAb was most potent when administered at the time of allografting. A delay in administration of mAb markedly reduced its immunosuppressive effects. Furthermore, additional doses of mAb given after the initial doses provided no increased immunosuppression and anti-CD2 mAbs did not delay rejection of second-set allografts. These findings support the notion that anti-CD2 mAbs interfere with afferent immunity and that CD2 is most important during the initial steps of an immune response. Investigation of the effect of anti-CD2 mAb on cellular immune functions demonstrated, in agreement with previous results, that it caused antigenic down-modulation of CD2 with relative sparing of CD3, CD4, and CD8 cell surface expression. Concomitantly the MLR, CTL, and NK responses were suppressed.     

Perfluorochemicals as US contrast agents for tumor imaging and hepatosplenography: preliminary clinical results

In animals, perfluorochemicals (PFCs) are effective ultrasound (US) contrast agents that produce hepatic, splenic, and tumor enhancement. The use of Fluosol-DA 20%, an emulsion of perfluorodecalin and perfluorotripropylamine, was studied in nine non-critically ill patients with cancer who had liver lesions. US studies without Fluosol were compared with studies obtained 24, 48, and 72 hours after Fluosol infusion. Vital signs and extensive laboratory analyses are performed before and after Fluosol infusion. Liver metastases from colonic, pancreatic, and gastric carcinoma exhibited rim or diffuse enhancement after a Fluosol dose of 1.6 g/kg or greater. Fluosol produced echogenic enhancement of the liver and spleen relative to kidney at a dose of 2.4 g/kg, allowing the detection of nonenhancing lesions. In addition, Fluosol at a dose of 1.6 g/kg or greater allowed detection of lesions not seen before contrast medium was administered in three of the seven patients studied. There was a mild increase in the level of serum glutamic oxaloacetic transaminase in two patients, one given 2.4 and the other 3.2 g/kg of Fluosol. Mild and transient allergic reactions without change in vital signs were experienced by two patients.     

Classical and anaplastic seminoma: difference in survival

Classical and anaplastic seminoma are traditionally treated with radiation therapy and are said to have the same prognosis. A retrospective study was undertaken of 90 seminoma patients treated with radiation therapy between 1961 and 1985. The classical group consisted of 71 patients of whom 50 had stage I and 21 had stage II disease. The anaplastic group consisted of 19 patients of whom ten had stage I and nine had stage II disease. The median follow-up time was 64 months for the entire group. The 10-year relapse-free survival rate for the classical group was 94% and for the anaplastic group was 70% (P less than .05). For patients with classical stage I disease, the relapse-free actuarial survival rate was 98%; for patients with anaplastic stage I disease, it was 64% (P less than .02). For the classical stage II disease group, the relapse-free actuarial survival rate was 84% and for the anaplastic stage II disease group, 75% (P less than .70). Four patients in the classical group (6%) had relapses; of these, one patient had local recurrence of tumor, and three had distant metastases. In the anaplastic group, four patients (21%) had relapses; two patients had local recurrence of tumor, and two had distant metastases. Therefore the data suggest a difference in survival and relapse rates between classical and anaplastic seminoma.     

Cytomegalovirus Disease in High-Risk Transplant Recipients Despite Ganciclovir or Valganciclovir Prophylaxis

The clinical patterns and predictors of cytomegalovirus (CMV) disease in kidney and/or pancreas transplant patients on ganciclovir (1.0 g po t.i.d.) or valganciclovir (450 mg po q.d.) prophylaxis were studied. This is a retrospective analysis of 129 transplant recipients. Median follow up was 12 months (range, 6-18 months). The overall incidence of CMV disease at 1-year post-transplant was 14% (4% tissue-invasive, 10% noninvasive). Seventeen of 18 patients were diagnosed with CMV after completion of 3 months' prophylaxis (median 8 weeks, range, 2-28 weeks). Induction treatment with thymoglobulin, and Donor +/Recipient - CMV status were the strongest predictors for the development of CMV disease. Cytomegalovirus incidence was not different between patients treated with ganciclovir or valganciclovir (15 vs. 17%, respectively). Valganciclovir (450 mg q.d.) is as effective as oral ganciclovir in CMV prophylaxis. High-risk individuals might require higher doses or longer duration of valganciclovir treatment.     

Evaluation of prophylaxis against hepatitis B in a large municipal hospital.

BACKGROUND: Perinatal transmission of hepatitis B can be interrupted by the administration of hepatitis B vaccine and hepatitis B globulin to the infants of carrier mothers. Universal screening of pregnant women makes this strategy possible. METHODS: To evaluate the implementation of universal hepatitis B surface antigen screening of women giving birth at Kings County Hospital Center during 1988, we reviewed laboratory records to find all women with a positive test result who might give birth. We also randomly reviewed records of women who gave birth to live infants to determine the percentage of screening in the population. Infants' charts were reviewed for documentation of maternal hepatitis B surface antigen status and administration of hepatitis B immune globulin and vaccine. RESULTS: Sixty infants who lived long enough to receive antihepatitis B prophylaxis were distinguished out of a total of 5146 births. Screening was done for from 66.8% to 80.4% (95% confidence interval) of the mothers of these infants. Although 44 of 60 infants received hepatitis B immune globulin and 39 of 60 infants received vaccine, only 27 of 60 received vaccine within 12 hours in combination with immune globulin (Centers for Disease Control-recommended therapy). CONCLUSIONS: Documentation of hepatitis B surface antigen in the infant's delivery room record was present in 23 of 60 infants. Those infants all received hepatitis B immune globulin and vaccine; 21 received hepatitis B immune globulin within 12 hours. Hepatitis B immune globulin was given within 12 hours to 8 of 37 infants who lacked documentation of hepatitis B surface antigen status on the delivery room record. These differences were highly significant (p less than 0.001) even when only the 40 patients who had documented prenatal screening at Kings County Hospital Center (21/23 vs 4/17). Prenatal care did not have any effect on outcome.     

Committing embryonic stem cells to early endocrine pancreas in vitro

A panel of genetic markers was used to assess the in vitro commitment of murine embryonic stem (ES) cells toward the endoderm-derived pancreas and to distinguish insulin-expressing cells of this lineage from other lineages such as neuron, liver, and yolk sac. There are two nonallelic insulin genes in mice. Neuronal cells express only insulin II, whereas the pancreas expresses both insulin I and II. Yolk sac and fetal liver express predominately insulin II, small amounts of insulin I, and no glucagon. We found that ES-derived embryoid bodies cultured in the presence of stage-specific concentrations of monothio-glycerol and 15% fetal calf serum, followed by serum-free conditions, give rise to a population that expresses insulin I, insulin II, pdx-1 (a pancreas marker), and Sox17 (an endoderm marker). Immunohistochemical staining shows intracellular insulin particles, and its de novo production was confirmed by staining for C-peptide. Most, but not all, of the insulin+ or C-peptide+ cells coexpress glucagon, demonstrating a differentiation pathway to pancreas rather than yolk sac or fetal liver. Addition of beta-cell specification and differentiation factors activin beta B, nicotinamide, and exendin-4 to later-stage culture increased insulin-positive cells to 2.73% of the total population, compared with the control culture, which gave rise to less than 1% insulin-staining cells. These findings suggest that stepwise culture manipulations can direct ES cells to become early endocrine pancreas.